VERIFICATION OF NONPRODUCTION OF CHEMICAL WARFARE AGENTS .1. DETERMINATION OF ORGANOPHOSPHORUS COMPOUNDS BY MICROCOLUMN LIQUID-CHROMATOGRAPHY WITH FLAME PHOTOMETRIC OR THERMIONIC DETECTION

Microcolumn liquid chromatography (micro-LC) with on-line flame photometric (FPD) or thermionic detection (TID) has been used for the determination of a series of organophosphoric and organophosphonic acids isolated from various sample matrices. Silica-based ion-exchange materials and polymer packings have been used as stationary phases. In order to improve the sensitivity (expressed in concentration units) of the technique, trace enrichment via a miniaturized precolumn (4 mm x 1 mm i.d.) and direct large-volume injections (1-10 muL) of aqueous samples have been studied. As an application, the verification of nonproduction of chemical warfare agents and their alleged use have been investigated by analyzing their hydrolysis products in spiked surface water and soil samples. The application of both the precolumn technique and large-volume injections permit the detection of organophosphorus acids in water and soil at the low ppm level.